FWE, definately. FOOK adds more guns, but all of FWE's guns are lore-friendly (as in, from the other games) and it rebalances the world quite brilliantly.
Grab the FOSE beta and it'll work with your steam 1.7 just fine. Get FOMM just because. FOSE because FWE needs it.
(As for radio, check out Existence 2.0, which is a lovely mod. There's also the STALKER soundtracks, which go with the atmosphere perfectly (because post-apocoloyptic DC and
The Zone have many similarities))